Card size is not the issue, both of them should in theory run fine with the potential 2TB cards.
But there is file limit set on our MTouch system, same on M0 Pro. Not yet sure if it will be same on M1s with its new platform, awaiting confirmation from software team.
Only way around file limit is if you use only folder browsing, that's in theory unlimited.
As mentioned in first post, M0 Pro will come with a balanced adapter for 4.4mm in packaging.
Also, the 3.5mm connectors is TRRRS, 5-pin.
There are actually 4 standards if you count the Sony PHA-3/Pono.